Jennifer Lawrence could win a Best Actress Oscar in February for “Silver Linings Playbook,” but this weekend she’s trapped in a horror movie called “House at the End of the Street.” The flick’s one saving grace seemed to be that Jen could sing. Yes, while watching the trailer, the world thought: Forget that little Mockingjay whistle — Katniss can sing! But while it sounded nice, it’s not J-Law. She recorded her own vocals for the scene, but a singer called Sarah Rayne ended up dubbing over the song. Psych!